My friend, first of all know this for sure, that there is life after death, and for a Christian it is beyond our comprehension on how beautiful and comforting it will be, so with that in mind that in itself should help ease your fear. Many people go through the so called fear of the unknown , and one way to alleviate that is to understand that you're not alone and many people have the same fear and it will subside. You're just twenty years old and emotionally people usually don't mature until the age of twenty five. I urge you to go to the nearest Church of Christ and study with them and if you're not already a Christian then I urge you to get baptized after studying with them. Asking questions when you don't understand when you're feeling a certain way is a great way to help yourself, because you learn that almost everything you are going through happens to others to and then you realize it's just not knowing is the cause of your problem. So in order to alleviate the problem keep doing what you did for this problem, which is ask others what they think, and you will see you're not alone and it's just a normal part of life that sometimes not knowing can cause the anxiety you're having, so hang in there, you're gonna be fine.
